140 SUPERFICIAL GEOLOGY OF DUNDAS VALLEY. 



No spring would rise from the rock unless there were fractures 

 or fissures in the rock enabling them to reach the surface. May not 

 these fractures be the sides of the canyon through which an ancient 

 stream passed, on its way from the present course of the Grand river 

 to the outlet through the valley. 



The evidence of the saline springs appears to me to show that 

 there is, a gradual underground drainage from the higher beds of the 

 Salina or Onondaga group toward Lake Ontario, or in the direction 

 of the lowest level. 



Of the present surface drainage enough has already been said 

 to show that, with the exception of one or two streams at the most, 

 the present system is altogether of recent origin. 



The only stream which I have observed that can really be 

 ascribed to be of pre-glacial or inter-glacial origin is the one at Ancas- 

 ter. From the drift filling its old channel, and from the position in 

 which it enters the valley, it can easily be inferred that this stream 

 existed at a time before the ice action set in, and that it entered the 

 the valley, when a current was flowing through the valley towards 

 Lake Ontario. 



The question of the origin of Dundas valley is one of consider- 

 able imporance, and if properly solved would prove valuable as a 

 key towards the solving of many of the problems connected with 

 Canadian Geology. 



We have already seen that two theories have been put forth — 

 one is that of glacial origin, and the other that it is due solely to flu- 

 viatile and aerial erosion. 



The supporters of both theories bring forward evidence to prove 

 their assertions. 



To briefly recapitulate the evidence supporting these theories 

 will require little space. Mr. George J. Hinde asserts that it is only 

 of glacier origin and points, in support of his theory, to the ice mark, 

 ings found throughout the whole district, and also to the beds of blue 

 glacial drift, or till, lying in the bed of the valley. He also points 

 out the form of Lake Ontario and the direction of the glacial striae 

 found at both ends of the lake. Another proof of the glacial origin 

 of the valley is the evidence of pre-glacial outlets from the south-west 

 end of Lake Erie towards the Mississippi valley and the absence of 



